1,721,004 research outputs found
Elettrificazione 25 kV-50 Hz della rete FS della Sardegna. Studio dell'influenza reciproca tra il sistema di alimentazione e quello di trazione
No full textThe article illustrates the methodology adopted for a prior determination of the maximum values of imbalance in the voltages of the high tension three-phase transmission network from the traction load envisaged by reason of the forthcoming electrification in single-phase ac (25 kV - 50 Hz) of the FS main line in Sardinia. The results obtained, both in fully in-service and out of service conditions of some of the main components of the electrical system, have made it possible to obtain indications regarding the adequacy of the solutions envisaged for the feed of the traction load, as well as to evaluate the influence of certain provisions to be respected during operation in the electric traction sub-stations, with the aim of reducing the imbalances in the three-phase network
Argos:un modello di simulazione dell'utenza residenziale per lo studio della gestione strategica della domanda di energia
No full textAl fine di ottimizzare le risorse energetiche disponibili e di ridurre gli investimenti per la costruzione di nuovi impianti di produzione, le strategie di controllo della domanda di energia elettrica più diffuse sono applicate in molti Paesi anche al carico residenziale. Per tale settore, però, la previsione dell'impatto della strategia prescelta risulta estremamente complessa in quanto è fondata su una stima della disponibilità dell'utente ad adeguare la propria domanda agli obiettivi proposti. Nel presente articolo viene descritto un modello di simulazione che a partire dal diagramma di carico di un'intera area di utenti residenziali consente di eseguire valutazioni sull'efficacia di politiche di gestione.The paper describes a simulation model of a residential users area to perform some evaluations relevant to different management policies of electric energy demand
Una metodologia di calcolo integrato del sistema di trazione a 2x25 kV,50 Hz. Applicazione alla valutazione degli effetti della frenatura a recupero in una tratta AV/AC
No full textNovembre 200
Distorsione armonica in un sistema di trasporto elettrificato metropolitano: indagine sulle linee di Roma
No full textEstimation of net harmonic currents due to dispersed non linear loads within residential areas
No full textThe paper deals with the problem of estimating net
harmonic currents injected by groups of non linear appliances present
within typical domestic customers mix.
To this aim a simulation based on "bottom-up" approach for accounting the cancellation phenomena among individual contributions hs been adopted and extended. The non linear appliances considered are Television set, Personal Computer, Fluorescent and Compact Fluorescent Lamp. The simulation operation of linear load has been taken into due account in order to simulate more closely real-life conditions. The simulation results are organised in tables which provide the estimate of main net harmonic currents (31th, 5th and 7th) likely to be monitored at the low voltage busbars supplying an end-use area composed exclusively by domestic customers.
The validity of the methodology proposed has been tested by
comparing simulation results with some field measurements from a
raidentidl area investigated
Cellular phone battery charges impact on voltage quality
No full textSeveral types of widespread battery chargers have been investigated in laboratory. A continuous harmonic current monitoring activity has been performed with a custom system in order to capture time-varying characteristics of harmonic absorption due to battery chargers typical duty-cycle. Finally, by using a novel method based upon laboratory tests, some curves have been proposed which allow predict voltage distortion impact at the point-of-common coupling (PCC) in presence of attenuation phenomena
Linee ferroviarie per alta velocità a 3 kV c.c.: predeterminazione della distorsione armonica nel sistema trifase di alimentazione
No full textA presentation is made in this article of a suitable methodology for the study of the predetermination of the harmonic distortion of the voltages and currents of the high voltage feed system of railway lines-for high speed electrified at 3 kV d.c. The illustration of the methodology is presented with applicative reference to the case of the new FS line Milan-Florence at present in the project phase. Lastly an analysis is made of the possibility of characterizing the stochastic variations of the harmonic currents due to the traction load on the basis of the average arithmetic values in pre-fixed time intervals and of the relative standard deviations, for the purpose of differentiating the disturbance in the feed system in terms of duration, also with a view to possible similar distinctions on the normative level
Time-varying harmonic currents from large penetration equipment
No full textA comprehensive review of analytical signal processing techniques applied to power systems and power quality applications. This reference book is unique in addressing time-varying waveform and harmonic distortions. It details many different approaches, pooling cutting edge material from university lecturers and practising power engineers to provide a wide spectrum of expertise. Divided into clear sections, the book discusses a range of topics includig: current and voltage variations; standards and measurement issues; advanced techniques such as spectral, time-frequency, probabilistic; and further methods, such as independent component analysis, and fuzzy logic. Case studies, real world data and examples (including basic application examples and sample waves from industrial sites) supplement the theory and demonstrate the methods shown. With extensive appendices in addition, this book is of great value to power systems, utility, maintenance and instrumentation engineers. It is also a useful source of information for researchers and consultants, university professors and graduate students in power systems and power quality areas
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